@jsmallwood We are currently working on release of an API that will cover all of this. As this is a new feature that came out this quarter we are still working on some of the surrounding support to the new relationship.

I wanted to provide some more context on this topic: Any endpoints that aren’t listed on https://developers.hubspot.com/ are considered internal endpoints and are subject to be changed or removed at any point without notice. The specific endpoints mentioned here were not intended to be used outside of the HubSpot app, and it’s not something we currently have a public endpoint for.

Did you need to include anything in the Body/Headers of the PUT request? It seems like all needed info (Portal ID & IDs of the two companies) is already included in the url, but I’m having trouble getting this to work.

I was able to get a response to puntouan’s GET request (below) simply by entering it in the address bar of my browser

All the info is in the URL, but you have to use your API key or OAuth token to make the PUT request.

And as @Derek_Gervais wrote, have in mind that your code can’t rely on this kind of undocumented calls, it’s just meant for getting or inserting data programmatically at a certain moment (e.g. migrating data from another CRM system).